System of control



R. E. FERRIS.

SYSTEM OF CONTROL.

APPLICATION FILED JULYIQ, 1917.

Patented Oct. 12,1920;

2 SHEETSSHEET 1.

5,0eed

WITNESSES: INVENTOR 4 /7 E, Ferris BY Mad 5 f 7 ATTORNEY R. E- FEHRIS.

SYSTEM OF CONTROL. APPLHZATION FILED iuLY19, 1911.

1,355,549. 'Patented 1ct.1z,1920.

2 SHEETS-SHEET 2. [2 9] 3 (A A y Currenf frw/gy WITNESSES: INVENTOR Ralph E. Ferris BY M I I ATTORNEY RALPH ENFERRIS, OF SWISSVALE, PENNSYLVANIA, ASSIGNOB TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A

CORPORATION OF PENNSYLVANIA.

SYSTEM OF CONTROL.

Application filed July 19,

To all wk am it may concern Be it" known that I, RALPH E. IERRIS, a

- citizen of the United States, and a resident of' swissvale, in the county of Allegheny field windings may and State of Pennsylvania, have invented a new and useful Improvement in Systemsof Control, of which the following is a speclfication.

My invention relates to systems of control for dynamo-electric machines and especially to the exci ation and controhof electric'railway motors and the like during regenerative operation.

One object of my invention is to provide an auxiliary generator that is mechanically coupled-to rotate with the main momentumdriven machines for exciting the main field windings during the regenerative period, a substantially constantly-excited field winding being provided for the auxiliary generator. A

More specifically'stated, it is the object of above-indicated character, wherein the auxiliary exciting armature is provided with a plurality of differentially-related field windings which are respectively energized from a constant-voltage source and from a second auxiliary armature that is rotatable with the other and is provided with a substantially constantly-excitec'l field winding, whereby the relative effects of the various be so varied as to prodesirable speed-current characteristic curves for the main machine- A further object of my invention 18 to provide an axle-driven exciting generator in conjunction with a regenerative control systern, whereby high-voltage circuits are entirely eliminated from the auxiliary system and a simply arranged and desirably stable regenerative system is obtained.

Other minor objects of my invention will become evident from the following description taken in conjunction with the accompanying drawings, wherein Figure 1 is a diagrammatic view of the essential circuits of a s stem of control embodying my inven-' tion; ig. 2 and Fig. 3 are curve charts servmg to represent various operating characteristics of the exciting machine and of the main machine of Fig. 1, respectively, during regenerative operation; and Fig. 4 is a diagrammatic view of a modified form of the present invention.

duce a plurality of Specification of Letters main.

my invention to provide a system of the 1917. Serial No. 181,587.

'Referring to Fig. 1 of the drawings, the system shown comprises supply-circuit conductors Trolley and Ground; a main dyna- PatentedOct. 12, 1920.

mo-electric machine having a commutatortype armature A1 and a field winding F] of the series type; a stabilizing resistor R1 that is associated with the main-machine circuits in a manner to be described; a plurality of auxiliary generating armatures l and 2 that are adapted to rotate with the main armatureAl by reason of being mounted upon, or driven from, the main-armature shaft or the truck axle, such as 3; a lurality of regulatingauxiliary resistors 2, R3 and R4; and a source of substantially constant voltage, such as a storage battery B, for exciting purposes to be set forth. a

The auxiliary generator armature 1, which is employed for exciting the main field winding F 1, in accordance with a subsequently traced circuit, is plurality of differential --related field windings 5 and '6, the field winding 5 being ener ized from the ba-tte B through resistor T12, and the field win ing 6, being energized differentially from the second auxiliary generator armature 2 through the resistor B3. A field winding 7 forthe second auxiliary generator armature 2 is connected through the resistor R4 across the battery B.

Assuming that the system is operating under normal regenerative conditions, the main armature or regenerating circuit is established from the supply-circuit conductor Ground, which is of positive polarity during regeneration, through conductor 10, stabillzing resistor R1, conductor 11, main armature A1 and conductor 12 to the trolley.

The main-field-winding or exciting circuit is established from the positive terminal of the auxiliary generator armature 1 1provided with a through conductors 13 and 10, stabilizing reterminal of the F1 and con-' regulating and very stable in its regenerative operation, as will be evident from the following discussion, As indicated by the solid arrows, representing regenerated current, and the dotted arrows, denoting main exciting current, both of these currents traverse the stabilizing resistor R1 in the same direction. Consequently, upon an incipient increase of regenerated current in the main armature Al, the correspondingly increased voltage drop across the resistor R1 immediately and inherently 7 reduces the voltage available for delivery to the main field winding F1 from the auxiliary generator armature 1. The converse action takes place in v the event of an incipient decrease of regen-' "erated current. In this way, a substantially constant current is returned to the supply circuit, irrespective of voltage fluctuations thereof, and the like.

Furthermore, by suitable design and proportion of parts, the difi'erential relation of the constantly-excited field winding 5 and the variably-excited field winding 6 for the auxiliary generator armature 1, causes the effective flux threading the armature 1 to be inherently increased as the speed of the associated vehicle and, therefore, of the axle 3 diminishes, to correspondingly increase the delivered voltage of the auxiliaryarmature l and, therefore, the excitation ofthe main field winding F1, whereby the regenerated voltage of the main armature A1 may be desirably maintained slightly in excessof the supply-circuit voltage. By reason of the substantially constant excitation of the auxiliary field windings 5 and 7 for the respective auxiliary armatures 1 and 2, the operation of the entire system may be closely predetermined and willalways be reliable and uniform.

On the otherhand, the illustrated systemv permits of convenient and efi'ectual adjustment or regulation of circuit connections to provide almost any desired type of operating characteristic, for example, the speedcurrent characteristic ofthe main machine. As graphically set forth by the voltagespeed curve of Fig. 2, suitable individual or collective manipulation of the variable resistors R2, R3 "and R4 will so varythe relative effects of the corresponding auxiliary field windings 5, 6 and 7 that the voltagespeed characteristic of the auxiliary gener- 65 ator armature 1 may be varied between the limits represented by the inverted U-shaped.

curves at, b, c and The speed-current characteristic curves obtained during the regenerative operation of the main machine, while employing the illustrated auxiliary exciting system, are represented in Fig. 3. Curves a and a" correspond to curve a of Fig. 2, with diiferent values of the stabilizing'resistor R1 employed in the main-armature circuit. Curves I I), c and d indieate'the type of operation that is obtained from the main machine when the auxiliary voltage-speed curves 6, 0 and 61, respectively, are utilized.

From the two curve charts, it is evident that almost any desired type of main-machine operating characteristic may be secured by suitable initial setting or subsequent variation of one or more of the auxiliary resistors R2, R3 and B4. In part1cu lar, the arrangement of parts may readily be made such that the main machine operates with a substantially constant ratio of field-winding ampere-turns to armature ampere-turns until the magnetic saturation 30 point of the main-machine magnetizable circuit is attained, thereby precluding the possibility 6f flash-over conditions and the like.

In some cases, it may be desirable to provide an inherent current-limiting feature in the main regenerating machine, wherebyan increase of vehicle speed is accompanied by any desired ratio of current increase until a predetermined current value 1 is reached, whereafter theregenerated current gradually decreases uponfurther increase of vehicle speed. Such characteristics are provided by operating the main machine in accordance with curves 0 or d of Fig. 3. Reference may now be had to Fig 4, wherein the system shown comprises the supply-circuit conductors Trolley and Ground; a pluralitylof parallel-related momentum driven dynamo electric machines respectively having commutator-type armatures A1 and A2 and field windings F1 and F2 of the series type; a plurality of stabilizing resistors R1 and R5 that are associated with the respective main machines in the manner set forth in connection with Fig 1; an axle-driven exciting or generator armature 19 for the main field winding; and an auxiliary motor having an armature21 and a series-related plural-section fieldwinding 1,10 22 for driving the familiar auxiliary mechanical loads upon a locomotive, such as anair-compressor or a blower for the main machine; and a relay device23 that is controlled by the voltage of 'the axle-driven generator 19 for the purpose of excluding from circuit one of. the sections of the'field winding 22, under predetermined conditions to be set forth.v

The axle-driven enerator armature 19 is proyided with a eld winding 20 that is sub ect to substantially constant excitation I from the batteryB, for example, through a resistor R6. The auxiliary armature 19 7 may be mounted upon thearmatureor truck axle 3, corresponding to the main armature A1, or upon the shaft 28 that is associated with the other main armature A2, the particular type-of driving'mechanism for the auxiliary generator armature being, of

' speed.

course, immaterial to my present invention, the only requisite being that the auxiliary armature rotates at the same speed as, or at a speed proportional to, the main-machine The field winding 22 for the auxiliary motor 21 is provided with a terminal top normally operating during the regenerative period, the main circuits are established from the supply-circuit conductor Ground through conductors 30 and 31 to junctionpoint 32, where the circuit divides, one

branch including stabilizing resistor R1, conductor 33, main armature A1 and conductor 34 to a second junction-point 35 and the other branch traversing conductor 36, stabilizing resistor R5, conductor 37, main armature A2 and conductor 38 to the junction-point 35, whence a common circuit is completed through conductor' 39 to the Trolley. v

The main exciting circuit is established from the positive terminal of the axle-driven generator armature 19 throu h conductor 40 to the junction-point 32, wl d ere the circuit divides, one branch traversing resistor R1, main field winding F1 and conductor 41 to another junction-point 42, and the other branch includin conductor 36, resistor R5, main field win ing F2 and conductors 43 and 44 to the junction-point 42, whence a common circuit is completed through conductor 45 to the negative terminal of. the axle-driven generator armature 19.

An auxiliary circuit is established from the positive terminal of the axle-driven armature through conductors 31 and 4 :51amture 21 of the auxilia .gnotor, the entire series-related field win ing 22 thereof and conductors 47, 44 and 45, to the negative terminal of the'armature 19.

To compensate for the gradual decrease of vehicle speed during the retardation period, the resistors R1 and R5 may be gradually excluded from circuit or the active circuit value of the auxiliary resistor R6 ma be gradually decreased;

y employing different ranges of exciting currents for the auxiliary field winding 20, a series of speed-current curves for the main machines, corresponding-to the curves a, a" and 6' shown in Fig. 3, 'ma be obtained and the entire combination, w ile aifording desirable regenerative operation, is very simple and inherently stable. The remaining curves, of the reversing type, such as 0' and 03, cannot be secured by the system of F ig. 4.

f, at any time during regeneration or otherwise, the voltage of the axle-driven arcally mature 19 decreases to a predetermined value, the correspondingly reduced energization of the relay device 23 allows the device to assume its lower. or circuit-closing position, whereby one section of theseriesrelated field win'ding22' for the auxiliary motor armature 21 is short-circuited or ex cluded from circuit. Such action automatiproduces an increased speed of the auxlllary motor,'in accordance with familiar principles, and thus, the aircompressor,

blower or other mechanical iload that is attached to the auxilia motor may continue to be utilized to its fu 1 capacity.

I do not wish to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the s irit and scope of my invention. I desire, tlierefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention 1.. The combination with a supply circuit and a main dynamo-electric machine adapted to return energy thereto and having an armature and a single series-type field windmg, of an auxlhary machlne armature rotatable with the main armature for exciting.

said field winding, and a substantially constantly-excited field winding for said auxiliary armature.

2. The combination with a supply circuit and a main dynamo-electric machine adapted to return energy thereto and having an armature and a single series-type field winding, of an auxiliary machine armature rotatable with the main armature for exciting the main field winding, a field winding for said auxiliary armature, and a battery for energizing the auxiliary field winding.

' 3. In a system of control, the combination with a supply circuit and a main dynamoelectric machine having an armature and a field winding, of a translating device connected inseries relation with said armature across the supply circuit, an auxiliary machine armature rotatable with the main armature for exciting the main field winding through said translating device, and a constantly-excited field winding for said auxiliary armature.

4. In a system of control, the combination with a supply circuit and a main dynamoelectric machine having an armature and a field winding, of a resistor connected in series relation with said armature across the supply circuit, an auxiliary machine armature rotatable with the main armature and connected through the main field windin across said resistor, a field winding for sai auxiliar armature, and a battery for ener gizing t e auxilia field winding.

5. The combination with a supply circuit and a main dynamo-electric machine adapt- 7 ed to return energy thereto and having an armature and a field winding, of an auxiliary machine armature rotatable with the main armature for excitin said field windinn. a constantly-excited field winding for said auxiliary armature, a second field winding therefor, and a second auxiliary armature rotatable with the other for exciting said second field winding.

6. The Combination with a supply circuit and a main dynamo-electric machine adapted' to return energy thereto and having an armature and a field winding, of an auxil-' 7. In a system of control, the combination with a supply circuit and a main dynamoelectric machine having an armatureand a field winding, of a translating device connected in series relation with said armature across the supply clrcuit, an aux liary machine armature rotatable with the main ar-.

mature for exciting the main field windins: through'said translating device, a constantly-excited field winding .for'said auxiliary armature, a. second field winding therefor, and a second-auxiliary armature rotatable with the other for exciting said second yfield winding.-

- 8. In a system of control, the combination with a supnlv circuit and a main dynamoelectric machine having an armature and a field winding. of a resistor connected in series relation with said armature across the supply circuit, an auxiliary machine armature rotatable with the main armature and connected through the main field winding across said resistor, a plurality of difierentially-related field windings for said auxiliary armature, a second auxiliary armature rotatable with the other for exciting one of the auxiliary field windings, a field winding for-said second auxiliary armature, and a battery for exciting the other auxiliary field windings.

9. In a system of control, the combination with a supply circuit and a main dynamoelectric machine having an armature and a field winding, of a resistor connected in series relation with said armature across the supply circuit, an auxiliary machine armature rotatable with the main armature and connected through the main field winding across said resistor, a plurality of differentially-related field windings for said auxiliary armature, a second auxiliary armature rotatable with the other for exciting one of the auxiliary field windings, a field winding for said second auxiliary field windings, a battery for exciting the other auxiliary field windings, and means for varying the efi'ect of said auxiliary field windmgs upon the 'main-machine speed-current characteristic.

In testimony whereof I have hereunto subscribed my name this 12th day of July, 1917.

RALPHJ E. rEnRIs. 

